Thread cutting and nipping device for sewing machines



Nov. 4, 1941.

THREAD CUTTING AND NIPPING DEVICE FOR SEWING MACHINES Filed 001;. 14, 1939 v Arhur NHq/le QZTMQ A/ A. N. HALE 2,261,680

Patented Nov. 4, 1941 UNITED STATES o' .1. ;A;

THREAD CUTTING AND'NIPPINCIJDEVICE FOR; SEWING'MACHINESL j Arthur N. Hale, Stratford, Conm, assignor to 'l he Singer Manufacturing Company, v.Elizabeth,

' N. J., a corporation of New Jersey a Application October 14, 1939,'Serial No. 299L455 12 Claims. (01.112-2527 This invention relates to thread-severing devices for sewing machines and has for its primary object to provide simple means for quickly and easilysevering the sewing thread extending from the. under face of the work to the thread-supply.

Another object of the invention is to provide improved means for severing the sewing thread extending from the under face of the work, without inverting the work. A still further object of the invention is to provide a sewing machine with simple means for severing the thread extending from the under face of the work while the work is disposed upon the sewing machine work-support and for nipping the end of the severed thread extending to the lower thread-supply.

The invention has also for its object to provide a sewing machine work-support, and more particularly the work-arm type .of work-support, with means disposedlabove said work-support for severing and nipping a severed end of thread extending fromthe under face of the work, which thread-severing and nipping means is constructed and arranged so as not to obstruct manipulation of the work incidental to stitching the same.

With these and other objects in view, as will hereinafter appear, the invention consists in the thread-severing and nipping device described in connection .with the accompanying drawing which illustrates a preferred embodiment of the invention and in which: v V

Fig. 1 represents aperspective view of the free end portion of a sewing machine'work-arm provided with the improved thread-severing and nipping. device, and showingthe sewing machine needle and presser-foot'. Fig. 2 is an enlarged top planview of the thread-severing and nipping device detached from the machine. Fig. 3 represents an enlarged longitudinal section of the thread-severing andnipping device, the portion of the workarm supporting said device being shown in section. Fig. 4 is an enlarged front end elevation of the thread-severing and nipping device.

The present improvement has been applied to a sewing machine which is particularly adapted for darning and embroidering, which sewing machine is in part shown in the drawing as having a horizontally disposed work-arm I provided with a cylindrical end-cap 2 having an openable endclosure plate 3. The end-cap 2 housesa looptaker mechanism of any usual or suitable construction (not shownyand complemental to the vertically reciprocatory thread-carrying needle 4 in the formation oflock-stitcheagsaid end-cap having the usual needle-aperture 5.

v thereby providing clips.

However, 55 guard ribs- 1 l.

the present invention is notlimited to any particular form of stitch-forming mechanism, as it will be obvious from the following description that there may be employed a thread-carrying chain-stitch looper .for cooperation with the thread-carrying needle, or some otherfisuitable or desired .form of stitch-forming mechanism. Opposed to the work-support is a presser-foot 6 of any usual or suitable construction.

Secured by screws I upon the cylindrical endcap 2 rearwardly and in the region of the needleaperture 5 therein, is the fiat shankof a thin knife-blade 8 having a narrow end portion thereof, which preferably extends lengthwise of the work-arm I, bent away from" said work-arm to provide an outwardly directed cutting edge 8 which is preferably. spaced slightly" from said work-arms Overlying the knife-bladeJ8 and secured by the screws .1 upon the'wo'rk-arm end-cap Zfis the rearward end of a guard-plate 9. The guardplate 9 has an outwardly bowed portion between its ends formed with substantially parallel thread-receiving slots l0 providing a plurality of laterally spaced knife-guarding ribs H overlying the cutting-edge 8' of the knife-blade 8, said ribs H preferably extending crosswise of said cutting edge and circumferentially of the end-cap 2.

The forward end portion l2 of the guard-plate 9 is depressed into a slot l3, provided in the endcap 2, so as to be substantially flush with the innerface of said end-cap. Extending upwardly from opposite sides of the front end portion l2 of the guard-plate, within and directly adjacent the ends of the slot l3, are'jdivergent ears l4 having inwardly or reversely bent free ends, Inserted into the clips l4 are the opposite end coils of a helical spring l5 which is held bowed outwardly'jbetween its ends by said clips, whereby adjacent coils at the upper side of the spring are spread apart to facilitate receiving a thread, and are compressed toward the lower side of the spring to nip the thread. The pposite longitudinal edges of the end-cap slot l3 confine the spring l5 against escape from the clips It.

When it is desired. to. sever the sewing thread a extending from the under face of the work to the end-cap needle-aperture 5, the work is merely slid rearwardly upon and generallycircumferen tiallyof the end-cap 2, therebydrawing the. thread a between any two coilsof the spring I5 and into a thread-receivingslot I ll'betweenthe' The thread a isthereby brought into engagement with the cutting edge 8 of the blade 8 and is severed by said blade. While the thread-nipping action of the spring I5 is such as to assist in severing the thread by retarding rearward movement of the thread, the severed end of the thread retained by the spring I5 is readily withdrawn therefrom in the succeeding stitching operation. f I

The simple construction of the thread-severing and nipping device described lends itself to its employment in a darning machine having a;

work-arm of small compass, without obstructing manipulation of the work. Furthermore, theide- I vice provides for severing the under thread whenever desired, without removing the work from the work-support or inverting the work, as-well as for temporarily holding the severed en'd' of the-- thread leading to the under thread supply. Thesefeatures are of particular advantage when darning tubular work, in that it obviates the necessity of turning the work inside out in order tosever the under thread, in the absence of some more elaborate and therefore complicated mechanically operated thread-cutter.

Having thus set forththe nature of the invention what I claim herein is:

1. A thread-severing device for a sewing ma- 'chine having a work-supportv provided with a prising a knife-blade secured upon and having a cutting edge directed outwardly away from said work-support, a guard-plate secured upon said work-support and having an outwardly bowed portion thereof overlying said cutting edge, said outwardly bowed portion of the guardplate being provided with-a plurality of laterally spaced guard-ribs and intervening thread-receiving slots extending crosswise of said cutting edge, and thread-nipping means disposed upon said work-support between said knife-blade and said needle-aperture,

3. A thread-severing device for a sewing machine having a work-support provided with a needle-aperture, and stitch-forming mechanism including a reciprocatory needle, said device comprising a knife-blade secured .upon and having a cutting edge directed outwardly away from said work-support, a guard-plate secured upon said work-support and having an outwardly bowed portion thereof overlying said cutting edge, said outwardly bowed portion of the guardplate being provided with laterally spaced guard- ,ribs. and intervening thread-receiving slots extending crosswise of said cutting edge, and thread-nipping means sustained by said guardplate in advance of said knife-blade. A 4. A thread-severing device for a sewing machine having a work-support provided with a needle-aperture, and stitch-forming mechanism including a reciprocatory needle, said device comprising a knife-blade secured upon and having a cutting edge directed outwardly away from said work-support, a guard-plate secured-upon said Work-support and having an outwardly bowed portion thereof overlying said cutting edge, said outwardly bowed .portiton of the guard-plate being provided with laterally spaced guard-ribs and intervening thread-receiving slots extending crosswise of said cutting edge, and thread-nipping means comprising a coil-spring sustained by said guard-plate in advance of said knife-blade.

5. A-thread-severing device for a sewing machine having a work-support provided with a needle-aperture, and stitch-forming mechanism including a reciprocatory needle, said device comprising a, knife-blade secured upon and having a cutting edge directed outwardly away from said work-support, laterally spaced guard-ribs extending crosswise of and overlying said cutting edge, and thread-nipping means comprising a coil-spring bowed outwardly between its ends and disposed upon said work-support in advance of said knife-blade,

6. A thread-severing device for a sewing machine having a work-support provided with a needle-aperture, and stitch-forming mechanism including a reciprocatory needle, said device comprising a knife-blade secured upon and having a cutting edge directed outwardly away from said work-suppo-rt, a guard-plate secured upon said work-support and having an outwardly bowed portion thereof overhanging said cutting edge, said outwardly bowed portion of the guardplate being provided with a plurality of laterally spaced guard-ribs and intervening threadreceiving slots extending crosswise of said cutting edge, and thread-nipping meanscomprising a coil-spring sustained by said guard-plate in vadvance of said knife-blade, said coil-spring being bowed outwardly between its ends to open the upper portions of the coils thereof and to compress the lower portions of said coils.

'7. A thread-severing device for a sewing'machine having a work-support provided with a needle-aperture and stitch-forming mechanism including a reciprocatory needle, said device comprising a knife-blade secured upon and having a cutting edge directed outwardly away from said work-support, a slotted knife-guard overlying said cutting edge and provided in advance of said cutting edge with clips spaced laterally of said knife-guard, and. a thread-nipping coilspring sustained by said clips in advance of the cutting edge of said knife-blade.

8. A thread-severing device for a sewing machine having a work-support provided with a needle-aperture and stitch-forming mechanism including a reciprocatory needle, said device comprising a cutting edge directed outwardly away from said work-support, said work-support having a slot in advance of and lengthwise substantially parallel to the cutting edge of said knife-blade, a slotted knife-guard secured at its rearward end upon said work-support to overlie said cutting edge and having a depressed forward end portion disposedv in said slot of the work-support, divergent'ear's rising from opposite sides of said knife-guard within said slot, and a thread-nipping coil-spring sustained at its opposite ends by said'ears and bowed outwardly between its ends.

9. A sewing machine having a reciprocatory needle, a work-arm free at one end thereof and lengthwise disposed substantially normal to the path of needle-reciprocation, said work-arm being provided with a needle-aperture, a knife: blade disposed upon said work-arm rearwardly and below the level of said needle-aperture, said a knife-blade secured upon and having knife-blade having its cutting edge extending substantially lengthwise and directed outwardly away from the work-supporting face of said work-arm, and laterally spaced guard-ribs overlying the cutting edge of said knife-blade and lengthwise extending substantially circumferentially of said work-arm.

10. A sewing machine having a reciprocatory needle, a work-arm free at one end thereof and lengthwise disposed substantially normal to the path of needle-reciprocation, said work-arm being provided with a needle-aperture, a knifeblade disposed upon said work-arm rearwardly of said needle-aperture, laterally spaced guardribs overlying and extending crosswise of the cutting edge of said knife-blade, and thread-nipping means disposed upon said work-arm between said needle-aperture and said knife-blade.

11. A sewing machine having a vertically re- .ciprocatory needle, a work-support provided with 12. A knife guarding and thread-nipping de- I vice for use in connection with sewing machines, comprising a knife-guard plate formed between its ends with an arched portion having laterally spaced knife-guarding ribs and an intervening v thread-receiving slot, said guard-plate being provided at one end thereof with laterally spaced and divergent ears upturned from the side edges of said plate at the arched side thereof, and a thread-nipping coil spring supported at its opposite ends by said ears and bowed outwardly between its ends.

ARTHUR N. HALE. 

